电气化铁路长大隧道区段牵引回流特性研究

由于电气化铁路长大隧道区段牵引供电系统特殊的电磁环境与电气拓扑结构,导致流经钢轨的牵引回流比例较大并产生过高的钢轨电位,因此需对隧道区段内牵引回流及钢轨电位分布规律开展深入研究。建立隧道区段直供带回流线方式下牵引网链式模型,计算接触网刚性悬挂方式下的牵引网导线阻抗参数,并推导多导体阻抗与导纳矩阵,利用Matlab/Simulink仿真平台建立长大隧道区段牵引供电系统仿真模型。在此基础上,分析机车运行时牵引回流在各回流通路中的分配规律,并研究综合接地系统对隧道区段钢轨电流、钢轨电位的影响。结果表明:电气化铁路长大隧道区段设置综合接地系统后,牵引回流经钢轨回流部分明显降低,并有效抑制钢轨电位抬升。

Research on Traction Return Current Characteristic of Long Tunnel Section for Electrified Railway

Due to the special electromagnetic environment and electrical topology of traction power supply system in long tunnel section of electrified railway,the proportion of traction return current through rail is more and the potential of rail is too high.Therefore,it is necessary to make the in-depth study on the regularity of traction return and rail potential distribution in tunnel section.The chain model of traction network under the mode of direct supply with return line in tunnel section is established,the impedance parameters of traction network wire under the mode of rigid suspension of catenary are calculated,and the impedance and admittance matrix of multi-conductor are deduced.The simulation model of traction power supply system in long tunnel section is built by using the simulation platform of Matlab/Simulink.On this basis,the distribution regularity of traction return in each return circuit during locomotive operation is analyzed,and the influence of comprehensive grounding system on rail current and rail potential in tunnel section is studied.The results show that: after the integrated grounding system is installed in the long tunnel section of electrified railway,the traction return current through the rail return part is obviously reduced,and the rail potential rise is effectively restrained.